ERCP is a study of the ducts that drain the liver and pancreas. Generally, the liver produces bile that is concentrated by the gallbladder and delivered to the duodenum (upper small intestine) via the common bile duct. The pancreatic duct joins the bile duct at the papilla of Vater where they drain into the duodenum through the sphincter of Oddi. ERCP generally includes cannulation of the biliary tree (which includes the bile duct, pancreatic duct, and hepatic ducts of the liver) by delivering a catheter through the working channel of a duodenoscope and into the biliary tree. A contrast medium is injected through the catheter to provide for diagnosis of problems in the liver, gallbladder, biliary tree and pancreas, such as gallstones, inflammatory strictures, leaks or cancer. Exemplary ERCP catheters are described in U.S. Pat. Nos. 5,320,602 and 5,383,849.
A wire guide is often used to assist in navigation of the catheter (or other endoscopic access devices such as sphinctertomes, balloons, biopsy devices, stent delivery catheters, dilators, etc.) through the sphincter of Oddi and into the biliary tree, often referred to as cannulation. Wire guides may also be used for deep cannulation of the biliary tree. Wire guides, however, carry the risk of trauma to structured segments of the bile or pancreatic ducts which can result in life-threatening infection, perforation or pancreatitis. Additionally, with the advent of new access devices permitting rapid exchange of multiple devices without the need for traditional “over the wire” or “long wire” exchanges (see, e.g., U.S. Pat. Pub. No. 2005/0059890, the disclosure of which is hereby incorporated by reference in its entirety) there exists the possibility for unintentional disconnection of the access device and wire guide.
Accordingly, there exists a need for a wire guide that assists in cannulation of the biliary or pancreatic ducts and minimizes the potential for trauma to the ducts. At the same time, it would also be desirable to reduce the chances of disconnection of the wire guide from newer access devices providing rapid exchange.